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2 years ago

Ecosystems do not have similar climates and every plant is different True or false

Chemistry

1 answer:

Soloha48 [4]2 years ago

4 0

This is false. Some plants are the same or at least very similar

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A wooden boat discovered just south of the great pyramid in egypt has a carbon-14>carbon-12 ratio that is 72.5% of that found

Kazeer [188]

The half life for C14 is 5730 years.

We assume that Carbon 14/ Carbon 12 ratio was steady for living organisms over time, the problem is actually telling us that
$\frac{Nt}{N0}$ = 0.0725 = $\frac{1}{2}$ ˣ

Take the natural logarithm and In on both sides.
ln(0.725) = ln $\frac{1}{2}$ ˣ
= - 0.3216 = xln ( $\frac{1}{2}$ = -0.6931x.
So x = (-.3216) / (-0.6931) = 0.464
or

t/t₁/₂ = 0.464
So t = 0.464 x t₁/₂ = 0.464 * 5730 yrs = 2660 years.

7 0

3 years ago

The molar concentration of sucrose in a can of soda is 0.375 M. How much sucrose would be found in a 2 liter bottle of soda of t

antoniya [11.8K]

Answer:

C) 0.75 mol.

Explanation:

Molarity is defined as the no. of moles of solute dissolved in 1.0 L of the solution.

So, The molar concentration of sucrose in a can of soda is 0.375 M means that: every 1.0 L of sucrose contains 0.375 mol of sucrose.

∴ 2 liter bottle of soda of the same concentration contains (2 * 0.375 mol = 0.75 mol) of sucrose.

<em>Thus, the right choice is: C) 0.75 mol.</em>

5 0

3 years ago

The standard free energy of activation of a reaction A is 81.9 kJ mol–1 (19.6 kcal mol–1) at 298 K. Reaction B is one million ti

klasskru [66]

Answer:

54.9 kJ/mol

Explanation:

The relation between the activation energy (Ea) and the rate constant (k) is given by the Arrhenius equation.

$k=A.e^{-Ea/RT}$

where,

A is a collision factor

R is the ideal gas constant

T is the absolute temperature

Reaction B is one million times faster than reaction A at the same temperature. So $k_{B}=10^{6} k_{A}$ .

Then,

$k_{B}=10^{6} k_{A}\\A.e^{-Ea_{B}/RT}=10^{6}A.e^{-Ea_{A}/RT}\\e^{-Ea_{B}/RT}=10^{6}e^{-Ea_{A}/RT}\\ln(e^{-Ea_{B}/RT})=ln(10^{6}e^{-Ea_{A}/RT})\\\frac{-Ea_{B}}{RT} =ln10^{6} -\frac{Ea_{A}}{RT} \\Ea_{B}=(ln10^{6} -\frac{Ea_{A}}{RT}).(-RT)=(ln10^{6}-\frac{89.1kJ/mol}{(8.314\times 10^{-3} kJ/mol.K).298K} ).(-8.314\times 10^{-3} \frac{kJ}{mol.K}.298K )=54.9kJ/mol$

8 0

3 years ago

asambeis [7]

Answer:

zinc forms more than one ion

3 0

3 years ago

Wewaii [24]

Answer: 0.0450 moles of $CaCl_2$

Explanation:

According to avogadro's law, 1 mole of every substance weighs equal to its molecular mass and contains avogadro's number $6.023\times 10^{23}$ of particles.

To calculate the moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar mass}}$

$\text{Number of moles of} CaCl_2=\frac{5.00g}{110.98g/mol}=0.0450moles$

Thus there are 0.0450 moles of $CaCl_2$

6 0

3 years ago